All 4wd lights on!

[Denisefwd93]

For no reason whatsoever! I thought it only happened when it was wet outside today it's bone dry and the lights came on. We haven't even started checking 4WD electrical components. Of course 4wd doesn't work at all, I knew that when I got this truck. But, I'm it expecting it to turn on by itself electrically! It does not get engaged electrically at all just all kinds of Pretty Lights for no reasons at all do I need to go fuse hunting?

 

[RonD]

Pretty much all the dash warning or notification lights get 12v with key on and are Grounded by "their" system to be lit up.
There is a "bulb test" for about 2 seconds with key on, when all systems will Ground their respective bulbs, then unGround them.

Both 4x4 lights on all the time would mean fuse is OK, should be fuse #7 in cab fuse box, but both are being Ground by the 4x4 control module OR.........both ground wires are shorted to ground somewhere, long shot.

In 1993 the two Ground wires from module to dash are brown/white stripe(4low), and Grey(4high)

The 4x4 switch doesn't control the lights, it connects to 4x4 module

 

[Denisefwd93]

Seems related to dancing gauges also Ron? Me truck gots a case of gremlins me thinks!

 

[RonD]

Maybe, but the 4 gauges are individually ground controlled, so a bad ground at battery would cause them to all act oddly at the same time and the 4x4 lights would also flicker, IF they were on, at the same time.

If the Volt gauge was acting up then I would expect, oil, and temp to also act up at that time, as they are 12v driven, the Fuel gauge uses a 5volt power supply so shouldn't act up at that time

Volt gauge reads instrument cluster voltage, just a simple 12v/ground connection in the cluster, so flickering volt gauge needle could mean local instrument cluster issue, or if say dome light or headlights also flickered then an alternator or battery connection issue

 

[Denisefwd93]

Now that you mention that, the fuel gauge is the only gauge it doesn't act up.

 

[Denisefwd93]

Still not high on the "list"
But, good news I think.

(Yes I'm still getting all the lights on whenever it's sitting overnight or it's wet out. )

I did look behind the jump seat and found the 4WD module, pushed the white button down with the ignition key on and have a steady red light which indicates a bad module. This it's all I've done so far,
Edit
Oops! I went back and reread the instructions I have to unplug things to do diagnostic test.


"a. If it flashes, this indicates the module is working properly. Go to step 3.

b. If it lights up and stays on, it indicates that the module is likely bad.*

c. If nothing happens, it means the module is either bad, or has no ground/power.

In either of these instances (b or c) power and ground should be verified before scrapping a 4x4 module.

The 4x4 module receives its power/ground through the 8 pin pigtail connector."

 

[Denisefwd93]

Back again, I did test "a" removed both plugs on the right side (front)
Turn key on push white button down and it flashes, that indicates a good module,
http://www.therangerstation.com/ho...ford-ranger-4x4-module-diagnosis-1994-older/

I left it unplugged, I hope that's okay I think Ron said it was.

When we change out the driveshaft I think I'll take out the shifter motor a couple more questions Ron will the transfer case leak fluid without the motor and place and unplugged missing will the truck run?

I have the housing from another shift motor that I could stick on there without the motor to keep oil from leaking out I think.

 

[Curious Hound]

It won't leak oil that way.

This message composed solely of recycled electrons. Go green!

 

[Denisefwd93]

Thank you Eric! good to know! thank goodness I have spare stuff laying around from other trucks!

anyhow, if anyone was wondering... What is inside that dashboard switch?

Another question for Ron, is there a check out procedure on the dashboard switch? as you can see it's far from simple lol

This is the same one that's in my truck but not the one from my truck "yet"

 

[RonD]

The 4x4 lights in the dash get 12volts with key on, like most dash indicator or warning lights.
Then they are Grounded to turn them on, so shorted wire doesn't blow a fuse it just turns light on

I have never taken one apart but it looks like mechanical switches, SW1 and SW2 on circuit board
You should be able to check it all out with an OHM Meter

1993/4 4WD wiring diagram here: http://www.therangerstation.com/forums/showthread.php?t=170637

You can see pins 1 to 8 on the switch in the lower left of diagram
Pin 1 is the common for the two switches
When you press the top button, 4high, you should see 0 ohms between, pins 1 and 2
Then high ohms or N/C when you press it again, switch OFF

Lower button, 4low, are pins 1 and 3 same test


On the Control module, lower connector, pins 4 and 5 activate the 4x4 lights by Grounding them, but..................
They are Grounded AFTER shift motor moves to correct position, they are not activated by pressing the buttons.

The 4x4 switch connecting pins 1 and 2, for example, tells controller to move shift motor to 4high position, which is set by the Contact Wheel in the shift motor housing
When motor has moved to correct position, controller then Grounds the Light bulbs, so never instant ON for the lights.

Controller will flash both lights if motor doesn't move, or contacts don't change, which is kinda the same thing

If pins 1 and 2 are disconnected, also 1 and 3, then controller moves shift motor to 2WD position and unGrounds all bulbs.

If all four 4WD lights are on then the 2 ground wires are shorted to ground, or the controller is bad, unplug controller's 5 pin connector and turn key on, if lights come on the wires are shorted to ground some where.
If lights stay off then controller was grounding them

 

[Denisefwd93]

Thanks Ron!
I probably should get a digital multi meter. With a LARGE readout lol.

I must say, the dashboard switch is anything mechanical aside from pushing the two buttons look at all those resistors. Lol

when we do the driveshaft we'll take shift motor down I have a feeling the motor is locked up in addition to shorted wires and Lord knows what else.

 

[Denisefwd93]

I don't drive at night very often but last night, I did happen to notice the dash lights are a little bit brighter now, (I could be wrong) and the gauges don't seem to be dancing as much now that I have the 4wd module disconnected.

Fixing the 4wd is still in conversation mode because there are many other things taking preference over this on the truck lol

 

[Denisefwd93]

It was rather obvious why I was getting 4wd lights on when wet, all the wires on the shifter motor are cut, broken, disconnected, I guess it was someone's attempt to check the wiring.

Didn't remove it, still not a high priority